SQL获取本周，上周，本月，上月第一天和最后一天[注：本周从周一到周天]

DECLARE @ThisWeekStartTime NVARCHAR(100),@ThisWeekEndTime NVARCHAR(100),--本周
            @LastWeekStartTime NVARCHAR(100),@LastWeekEndTime NVARCHAR(100),--上周
            @ThisMonthStartTime NVARCHAR(100),@ThisMonthEndTime  NVARCHAR(100),--本月
            @LastMonthSartTime NVARCHAR(100),@LastMonthEndTime NVARCHAR(100),--上月
            @LastestHalfYearStartTime NVARCHAR(100),@LastestHalfYearEndTime NVARCHAR(100),--近半年
            @LastestOneYearStartTime NVARCHAR(100),@LastestOneYearEndTime NVARCHAR(100)--近一年
            
    SELECT @ThisWeekStartTime= CONVERT(nvarchar(10), DATEADD(wk, DATEDIFF(wk,0,DATEADD(dd, -1, getdate()) ), 0),121)--本周开始时间
    SELECT @ThisWeekEndTime= CONVERT(nvarchar(10), DATEADD(wk, DATEDIFF(wk,0,DATEADD(dd, -1, getdate()) ), 6),121)--本周结束时间
    
    SELECT @LastWeekStartTime=  CONVERT(nvarchar(10),DATEADD(wk, DATEDIFF(wk,0,DATEADD(dd, -7, getdate()) ), 0),121)--上周开始时间
    SELECT @LastWeekEndTime= CONVERT(nvarchar(10), DATEADD(wk, DATEDIFF(wk,0,DATEADD(dd, -7, getdate()) ), 6),121)--上周结束时间
     
    SELECT @ThisMonthStartTime=CONVERT(nvarchar(10),dateadd(dd,-day(getdate())+1,getdate()),121)--本月开始时间
    SELECT @ThisMonthEndTime=CONVERT(nvarchar(10),dateadd(dd,-day(getdate()),dateadd(m,1,getdate())),121)--本月结束时间
    
    SELECT @LastMonthSartTime=CONVERT(nvarchar(10),dateadd(dd,-day(dateadd(month,-1,getdate()))+1,dateadd(month,-1,getdate())),121)--上月开始时间
    SELECT @LastMonthEndTime= CONVERT(nvarchar(10), dateadd(dd,-day(getdate()),getdate()),121) --上月结束时间
 
    SELECT @LastestHalfYearStartTime= CONVERT(nvarchar(10),  dateadd(dd,-day(dateadd(month,-6,getdate()))+1,dateadd(month,-6,getdate())) ,121)--近半年开始时间
    SELECT @LastestHalfYearEndTime=CONVERT(nvarchar(10), dateadd(dd,-day(getdate()),getdate()),121)--近半年结束时间
    
    SELECT @LastestOneYearStartTime= CONVERT(nvarchar(10), dateadd(dd,-day(dateadd(month,-12,getdate()))+1,dateadd(month,-12,getdate())) ,121)--近一年开始时间
    SELECT @LastestOneYearEndTime=CONVERT(nvarchar(10), dateadd(dd,-day(getdate()),getdate()),121)--近一年结束时间

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当前时间 select getdate()
当前时间周的起始日期（以周一为例）select DATEADD(week,DATEDIFF(week,0,getdate()),0)
上周起始：select dateadd(week,-1,DATEADD(week,DATEDIFF(week,0,getdate()),0))
上上周起始：select dateadd(week,-2,DATEADD(week,DATEDIFF(week,0,getdate()),0))
上上上周起始：select dateadd(week,-3,DATEADD(week,DATEDIFF(week,0,getdate()),0))